Question

The potential energy of a molecule on the surface of a liquid compared to one inside the liquid is :

• A. zero
• B. lesser
• C. equal
• D. greater

Answer 1

The correct option is D greater

When the surface area of a liquid is increased, molecules from the interior of the liquid rise to the surface. As these molecules reach the surface work is done against the cohesive force. This work is stored in the molecules in the form of potential energy. Thus, the potential energy of the molecules lying in the surface is greater than that of the molecules in the interior of the liquid.